Polycrase-(y)
Polycrase-(Y)
A variety of Minerals
What is Polycrase-(y)?
Polycrase or polycrase-(Y) is a black or brown metallic complex uranium yttrium oxide mineral with formula: (Y,Ca,Ce,U,Th)(Ti,Nb,Ta)2O6. It is amorphous. It has a Mohs hardness of 5 to 6 and a specific gravity of 5. It is radioactive due to its uranium content (around 6%). It occurs in granitic pegmatites. Polycrase forms a continuous series with the niobium rich rare earth oxide euxenite. It was first described in 1870 at Rasvag, Hidra (Hittero) Island, near Flekkefjord, Norway. It is found in Sweden, Norway, and the United States.
Market Value Factors
Pricing varies for every rock and mineral, so use these universal factors to gauge Polycrase-(y) before comparing listings or appraisals.
Size & Weight
Larger, intact specimens usually command higher prices.
Rarity & Demand
Scarce material or popular varieties sell at a premium.
Condition & Finish
Chips, repairs, and heavy wear lower value; clean prep helps.
Treatment & Provenance
Untreated specimens with documented locality are prized.
Quick Facts
Physical Properties
- Color
- Black
- Hardness (Mohs)
- 5 - 6
- Rock tumbling
- With care
- Density
- 4.9 - 5.1 g/cm³
- Streak
- Yellowish, grayish, reddish brown
Chemical Properties
- Chemical Formula
- Y(Ti,Nb)2(O,OH)6
- Elements
- H, Nb, O, Ti, Y
Also Known As
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Polycrase-(y) FAQs
How do I identify Polycrase-(y)?
Polycrase-(y) can be identified by its hardness of 5 - 6 on the Mohs scale, Black color. Look for these key characteristics when examining specimens.
What color is Polycrase-(y)?
Polycrase-(y) typically appears in Black. Color can vary depending on impurities and formation conditions.
How hard is Polycrase-(y)?
Polycrase-(y) has a hardness of 5 - 6 on the Mohs scale. This gives it moderate hardness.
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